Hospitals can provide a wide variety of lab tests to better understand our ailments. But have you ever wondered what happens to the sample after it’s in your doctor’s test-tube but before you get results? The answer is usually complicated and slow lab work; requiring lots of individual little steps to isolate and measure some specific molecule in your body. (Think of PCR-based COVID-19 tests). But not all tests require lab work.
You’re probably familiar with some paper-based diagnostic tools like checking the chlorine or pH level of your swimming pool. These are “dipsticks” of special papers and suitable for large volume samples. But what if you only have a couple drops to spare? For example, a diabetic is usually monitoring their blood’s glucose molecules with only a few drops of blood on special paper, then adding that paper to a measuring device. But you still need that small electronic device to know your blood glucose levels! This device requirement makes testing and diagnosis less accessible to people around the world. What if you could make a paper-based diagnostic tool, that works with tiny volumes, but doesn’t need any other equipment, or fancy software, or a trip to the hospital to get your answer? This is exactly why researchers are excited about paper-based microfluidic devices.
Pregnancy tests are one of the best examples (See Figure 2.4) of how researchers have automated a complex laboratory test onto a single device someone can purchase from any local pharmacy, at a relatively low cost, to get an answer within minutes, inside their own home. These tests actually measure a specific hormone, but it’s presented as a color indicator. Inside the device is porous media, to help move the sample, and a few different reagents in a specific order that generate the chemical reactions so you can see your test result as an easy to interpret color. No extra fancy machines, no hospital visit, rapid results, and relatively affordable disposable devices make pregnancy tests a success story. But this was commercialized in 1988, and urine samples are generally thought to be larger volume samples. There are still many more potential uses of paper-based diagnostic tools, using small-volume blood samples, yet to be developed.
This evening we have Lael Wentland, a PhD candidate in the College of Engineering, who is discussing her ongoing research on developing paper-based microfluidic tests for rare diseases. A central pillar of her work is to make healthcare more sustainable and accessible for a greater number of people, but especially those in more remote settings. The World Health Organization has an ASSURED criteria for the development of more paper based diagnostics to help guide researchers. The ASSURED criteria principles require the device be: Affordable, Sensitive, Specific, User friendly, Rapid and Robust, Equipment free and Deliverable to end users.
Using this framework, Lael has already developed one tool to monitor a metabolic disorder, and continues to work on another rare biomolecule. She started her research at OSU on phenylketonuria, a metabolic disorder where your body cannot breakdown a key amino acid (phenylalanine) found in foods. If you get too little of this amino acid, your body can’t make all the proteins it needs for growth, repair, or maintenance. Too much of this amino acid can cause seizures and developmental delays. Keeping close tabs on this phenylalanine is needed for people with this disorder because you can alter your diet to suit your body and remain healthy. But the current tests to monitor this amino acid is not as readily available as one may need. This is why Lael worked to make a paper-based microfluidic device that would adhere to the ASSURED criteria to make this more accessible for anyone. Lael was way past the proof-of-concept stage of her device, and was already recruiting subjects to test their blood using her new device when COVID-19 become prominent in March 2020. That’s one reason she pivoted to monitoring another rare disorder using similar principles.
We’ll get into that, and so much more, Sunday 7pm on 88.7FM KBVR.
Did you miss the show Sunday night? You can listen to Lael’s episode on Apple Podcasts!